The purpose of this Multidisciplinary Center is to explore the neural bases of language and cognitive development from 5 years to adolescence, combining behavioral, neurophysiological and neuroanatomical methods to study the same populations of children at risk for language and cognitive disorders. Project 5 will focus on children with specific language impairment, compared with high-functioning individuals with autism. Project 2 will follow children with different forms of early focal brain injury (FL), including injury to the classical language ares, providing us with a prospective look at the reorganizational processes that underlie recovery from deficit in this group. project 4 will compare Williams Syndrome (WMS), a rare form of mental retardation in which language abilities eventually surpass other cognitive domains, and Down Syndrome (DNS), a profile of retardation that complements WMS in many respects; this project provides a unique opportunity to study the "fractionation" of language and cognition. Project 8 will apply new " on-line" (reaction time) methods to study the real time properties of language processing in normal and abnormal populations. Project 9 will apply more traditional "off-line" (untimed) methods to study language and affective expression ina discourse context. Project 10 will use a combination of "on-line" and "off-line" technique to study the development of spatial cognition and attention. project will explore the neural correlates of these contrasting profiles, through detailed electrophysiological studies of brain activity associated with linguistic and non-linguistic stimuli at each stage of development. The projects are served by 2 core facilities; Administration & Statistics Core and Diagnostic Core. In addition, all projects will draw from a common pool of experimental methods, permitting systematic comparisons by age, domain and population. The diagnostic will coordinate studies using structural magnetic resonance imaging (MRI); pilot studies using functional MRI will be conducted by the diagnostic Core and Project 3. The Multicenter is administered by the UCSD Center for Research on Language, in association with seven UCSD academic departments, the SDSU Departments of Psychology and Communicative Disorders, Children's Hospital Research Center (CHRC), and the Salk Institute for Biological Studies. Findings from the Multicenter are relevant to our understanding of normal and abnormal brain development, and the alternative forms of brain organization for language and learning that can emerge under pathological conditions. These insights, in turn, have practical applications for diagnosis, management and intervention with children at risk for language and cognitive impairments, and are of interest to families, physicians and educators.